A study from Sotheby's International Realty looked at the purchasing plans and behavior of wealthy real estate buyers. When asked about their top choice for their next real estate purchase, the largest number cited a waterfront property.

In the U.S., 41 percent said waterfront would be their top choice for their next purchase. In the U.K., it was 49 percent, while in Brazil and China waterfront was the choice for 51 and 54 percent of respondents, respectively.

The top search on Sotheby's website in 2013 was also "waterfront," at 42 percent, according to the company. The term "mountain" was second (21 percent), followed by "country living."

Part of the reason for the water focus may be aesthetic. Water views provide the ultimate "wow factor" for big homes. But there's also an investment reason. Waterfront is scarce, especially in affluent regions like the Northeast, Florida and the West Coast.

When asked about what factors influenced their real estate purchase, a "return on investment" ranked just behind "family needs" and "location."

Source: Douglas Elliman

When U.S. respondents were asked about specific features they want in the house, 1-in-4 cited a deep-water dock. It ranked higher than "space for art" or "helipad."